Detergent compositions

ABSTRACT

Detergents for use with hard water consist of one or more cleansing agents and a compound of tetra-phosphoric acid (H6P4O13), e.g. sodium tetraphosphate. Cleansing agents specified are alkyl sulphonates, sodium bisulphite, sodium hypochlorite, oxalic acid with or without sodium sulphate, and sodium or potassium soap which may or may not contain free fatty acid, borax, ammonium compounds, orthophosphates, soda ash, and rosin.  Specification 8197/01, [Class 28], is referred to.

Fatented Apr. 20, 1937 NlTEl) STATES,

v PATENT o-F' I E DETERGENT COMPOSITIONS Augustus n. Fiske, Warren, R. 1., assignor to Rumford Chemical Works, Rumford, It. I. a

No Drawing. Application October 5, 1935., set-n1 No. 43,716

1 Claims. ,(01. 81-5) admixtures therewith, and process of applying the same.

The object of my invention is to provide a detergent or cleanser, as, for example, a soap containing in intimate admixture therewith a compound of a thiotetraphosphoric acid or an alkali metal salt of a thiotetraphosphoric acid,

so as to obtain an effective softening effect upon water in which the detergent is used, as well as 1 the process of applying the same. A further object is to dissolve the combinations of the soap; or other detergent, with the substances producing the hardness of water, loosen the dirt by dissolving the alkali earth compounds present,

20 improve the sudsing value of the soap, as well as to regenerate any of the soap that is combined with the alkali earthderivatives present.

By a thiotetraphosphoric acid, as referred to herein, I mean the acid corresponding to any of 5 the thiotetraphosphates, by which term I mean to include all thiotetraphosphates of any or all of the alkali metals where a sulphur atom has replaced one or more of the oxygen atoms in the 0 cember 24, :1935, andMethod of preparing thiotetraphosphates and product thereof, Ser. No. 756,458, filed December -7, 1934, Patent No. 2,033,913, granted March 17, 1936 in which I am the joint inventor with Charles S. Bryan. In fact it is to be understoodthat I may, in the composition, use any of the thiotetraphosphates in which one of the acid radicals is present as follows:

50 P4O12S, P401182, P401 083, P401184, P40BS5,

P40'1Sc, PiOsSq, P405813, P404313, P403810, P402811, P4OS1a, P4513,

and which may be combined with any or all of 55 the alkali metals to form corresponding salts therewith. For example, in the case of the radi cal P4012S, the corresponding acid is HePsOxaS, and there can be six different salts of a particular alkali metal derived therefrom, asfollows:

In fact, if desired, there can be used for-this purpose a salt in which any ofthe above radicals 10 is combined with any two or more of the alkali metals replacing the-hydrogen of the thiotetraphosphoric acid.

Practically all natural waters contain salts of the alkali earth metals, as, for example, calcium and magnesium in solution in small quantities, thus producing the property known as hardness. This has an important bearing in washing operations because the alkali earth compounds tend to form an insoluble precipitate with the fatty acid radicals of thesoap, resulting in a waste of the soap by withdrawing it from a cleansing action. Also, the insoluble soaps thus formed produce a coating on the object or textile being cleansed, which is not easy to remove. Soap has no sudsing power with hard water until all the hardness has been take care of by the soap and it is only the soap in excess of that amount which provides the sudsing power. Therefore, the soap s which has combined with the compounds producing hardness is wasted. It 'is well recognized that the sudsing ower of soap is the measure of its cleansing power, therefore the presence of a material which will increase this power, by soff tening the water or taking care of the alkali earth basic radicals in the water or regenerating the soap from its'combination with the compounds producing hardness, as in accordance with my invention, has an important value in the saving of soap. 40

Thus, in accordance with the present specification, wherever I refer to a thiotetraphosphate I also include any salt of the general formula Mx 4oxsy O1 MarHyP40zSy O1 Mal-3132404811, fOI example, where M refers to an alkali metal or basic radical, N refers to anotheralkali metal basic. radical, and the subscript letters 2, y, and 2 applied to each of the diflferent atoms in the formula, may be a number or zero, but wherein they are all derived from the normal tetraphos- 5 phoric acid discovered byiEleitmann 8: Henneberg in 1848, referred to in Roscoe 8: Schorlemmers Treatise on Chemistry, Vol. I, MacMillan 8t .00., Ltd., 1905, page 656 and isolated by Rakuzen'tz Arseneev, Chem. .Ztg. 1923, pages 47,

195. The formula of this tetraphosphoric acid is given by them as HeP4O13.

In accordance with my invention I provide in the presence of the detergent a water soluble compound of any of the said thiotetraphosphoric acids, preferably a water soluble salt of. any of the above thiotetraphosphorlc acids, as, for example, sodium, potassium or ammonium salts thereof, as well as an effective process of utilizing the same.

The soaps which I may use, furthermore, may be comprised of one or more compounds of a fatty acid with an alkali metal with or without the presence of excess free alkali and other ingredients, such as borax, ammonium compounds, orthophosphates soda ash, rosin, etc., in any desired proportions.

I have found, for instance, that a mixture of a water-soluble compound of any of the said thiotetraphosphoric acids, and particularly any of the thiotetraphosphates such, for instance,

as a sodium thiotetraphosphate with soap,

as, for example, sodium soap, or a sodium soap powder, or any detergent mixture, depending upon the presence of a sodium soap, for example, will provide a more efliclent washing than the soap or detergent without the presence of the thiotetraphosphoric acid compound. Furthermore, while the softening of the water beforehand with the thiotetraphosphoric acid compound is beneficial even "when adding the soap thereto afterwards, this does not give as satisfactory sudsing or cleansing results, as in the case of the intimate admixture of the soap or detergent with the thiotetraphosphoric' acid compounds at the time when they are added to the water. If the water is treatedwlth the thiotetraphosphoric acid compound in a sufiicient amount to soften the hardness thereof and then used,

with soap subsequently added for washing, the bubbles formed are large and coarse. ever, the soap is intimately mixed with the thiotetraphosphoric acid compound and then added to the water, the suds are found to be of a fine,

texture and much more dense under the same sudsing conditions. In the former instance it is found that the lather is much thinner, whereas in the latter case the lather has a velvet-like feel not present in the former instance. In the latter instance a more superior sudsing power is also attained. The said mixed materials may be in their dry form.

My theory of this action is that a certain effective concentration of a common ion in water is what causes the soap to give satisfactory suds.

' This is based on the fact that the table used sis by Wilfred w. Scott, fourth edition, 1934, seventh printing, vol. 11, page 1439. I have confirmed this theory in the following way. I determined the hardness of a natural water by the standard method using a 50 cc. charge and titrat- If, howing with a standard soap solution. This titration took 2.4 cc. of the standard solution which indicated by the standard table of equivalents a hardness of 24.7 degrees. I then took a similar 50 cc. charge of the same water and added 5 cc. of a 1% solution of sodium chloride, thus adding a common ion in the form of a well dissociated salt. Then on titrating the charge once more I obtained 19.5 of hardness as my result. Thus it is seen that the addition of the common ion (sodium) caused the sudsing to take place with less soap consumption giving an erroneous result tokeep the soap in undissociated condition, than if it is dispersed throughout the solution as in a water just softened by the thiotetraphosphate. Thus it is seen that having the sodlum'thiote'tra-, phosphate directly dispersed throughout the body of the soap, and having the material dissolved simultaneously with the soap, I have a greater concentration of sodium ions about the soap as it dissolves and, therefore, a quicker and more concentrated sudsing power. This theory will account for the peculiar action of the sodium ion of the thiotetraphosphate but in addition I have the thiotetraphosphate ion and it is this ion which at the same time protects the fatty acid radical from the action of the calcium or magnesium compound hardness of the water. Being simultaneously dissolved with the soap it is present in concentrated form with the soap as they both dissolve and, therefore, the thiotetraphosphate keeps the calcium or magnesium ions from combining with the fatty radical of the soap by combining with the calcium ion itself to form a more complex radical, which, while it may restrict the sudsing power of the solution to some extent in an excess of the soap, yet, especially in the lower concentrations, will assist the sudsing power. This complex radical is soluble in water.

A thiotetraphosphate has the power of softening water, as set forth in my copending applications above referred to. Therefore, in dispersing the thiotetraphosphate throughout the soap or detergent there is produced a sudsing action due to the concentration of the sodium ion at the time of the solution of the soap and also the softening power of the thiotetraphosphate ion, in that it combines. with the calcium or magnesium to remove it from the sphere of influence of the fatty acid radical of the soap. These eifects contribute beneficially to each other. v

In order to'show the dissociation of the soap moreclearly-I will give the following balanced reaction asillustrative:

The compound represented by the chemical radical'cHsicHzhiCo-s is .the radical of palmitic acid and is given only as an illustrative example of an ingredient in the soap.

If I add some sodium thiotetraphosphate to the solution in concentrated form as the soap dissolves with the dissolving of the thiotetraphosphate I first have the thiotetraphosphate dissoclation' as follows: I will give the dissociation acraovi reaction on a theoretical basis using the monothiotetraphosphate as illustrative by gradual stages of equilibria until finally suificiently dilute I could have a P4013S as'the ionic condition.

According to my invention, the concentration of the thiotetraphosphate while in contact with the soap :as it dissolves, will tend to remain high and thus maintain a high concentration of the Na+ ions in the neighborhood of the soap,as it is gradually consumed. Thus, with a high concen- .tration of Na+ ions about the soap 1 have a fatty acid salt (or soap) formed to bring the tendency of the Na.+ ions to force the reaction;

of the dissociation of the soap toward the left and so with this shift of the equilibrium I have a greater concentration of undissociated sodium conditions to a balance once more. Likewise, this tends to make the soap give a sudsing value at a lower concentration as this sudsing value depends on the concentration of undissociated soap and not on the total concentration of soap in the solution in the dilute conditions referred to. when the soap is dissociated the addition of more Na+ ions to the right hand side of the equilibrium representing the dissociation of the soap, tends to cause more undissociated soap to form on the left hand side of the equation until equilibrium is once more obtained. Y

As natural waters vary in their hardness so the soap or detergent which contains a softener for the natural hardness should vary its poportional quantity of softener in a similar manner, and I have found that it requires, in practical work, approximately half as much thiotetraphosphate by weight as there is hardness by weight if I'calcmate the hardness in terms of calcium carbonate, to take care of the hardness. Therefore, we can see that a gallon of water 100 of hardness (100 parts per million of equivalent calcium carbonate) 3 contains 6 grains of calcium carbonate and I may calculate about 3 grains of thiotetraphosphate for the equivalent soap to be used in this gallon to yield an effective softness. I have found'that it, takes about 15 grains of soap to a gallon of water for ordinary washing, so that in this instance it would be correct to use three grains of the thiotetraphosphate to every 15 grains of soap or 20% of the weight of the soap. However, it is found that-the proportions can be very widely varied in actual cleansing operations.

water may be used and sometimes the best results are obtained with three times to five times the amount of the calcium carbonate equivalent hardness, of thiotetraphosphate. This would make it necessary to vary the percentage of my thiotetraphosphate in my detergent mixture at least from 10% to 50% of the mixture. For this reason I do not confine myself to any particular proportion of my thiotetraphosphate to any parparticular quantity of soap or detergent, but that the quantity may be varied to suit the market or locality where the soap is to be used and on a basis of the hardness contained in the water of that locality. I

According to the U. S. Geological Survey the hardness of water is expressed in terms based on parts per million and one part per million of For instance, it is found 'that as much as'25 grains of soap pergallon of equivalent calcium carbonate is expressed by them as a degree of hardness. They classify the natural waters of the United States as follows:

. 1 Degrees Hardness or under is soft 55 Moderately soft 55 to Moderately hard 100 to 200 Excessively hard 200 to 500 Therefore, for soft or moderately soft waters I should use up-to 20% of my thiotetraphosphate and for hard waters proportionately larger amounts should be used. I have found, however, in certain sections ofthe country where the water contains under 20 of hardness that 5% of the thiotetraphosphate of the soapor even less may be used effectively to soften the water for the soap. Of course, instead of the sodium thiotetraphosphates above mentioned, a potassium thiotetraphosphate may be used, and instead of a sodium soap, a potassium soap may be used, although when using a potassium soap it is desirable to use a potassium thiotetraphosphate therewith.

Also, a liquid soap will generally contain both' sodium and potassium bases and thiotetraphos phates thereof.

,I have found, furthermore, that any of these compounds of thiotetraphosphoric acid will dissolve calcium or magnesium compounds from any constituent 'of the dirt or contaminating material which is to be removed in the process of the cleaning. Thus, the thiotetraphosphate will dissolve the calcium compound instead of allowing it'to combine with the soap and so destroy and consume the soap. Also, the thiotetraphosphate causes the calcium compound to remain soluble and prevents it from interfering with the action of the soap. At the same time, in the process of cleaning, if I dissolve out one constituent of a' material, as, for instance, the first to be removed in cleansing operation, then. the other portions of the dirt will obviously be loosened or set free by this partial solvent action.

Furthermore, when the thiotetraphosphate loosens the dirt by dissolving from it its calcium constituent, then it is important to have the soap in admixture with it in sufficient concentration to remove the dirt from the material which it is desired to clean. Thus the thiotetraphosphate in the detergent not only acts as a water softener and in this way a soap saver, but also as an important auxiliary to the detergent as it is a dirt loosener itself. There is another phase of the action of my invention which is important from the economy-standpoint, If, for example, common soap is used to wash an object pounds which have combined with the fatty acid radical of the soap and reduced its cleansing power. The act of combining the thiotetraphosphate with these dirt forming bases sets free the fatty radical of the soap and when thus regenerated it is once more ready to act as a cleanser in its rejuvenated form. Thus. the soap ismade to be more eflicient and far-reaching in its ac tion. A great economy is thus effected in the consumption of soap in this phase-of the cleansing process. x

5 I of course do not confine myself to ordinary soaps in my invention as the same extends to all varieties of detergents an cleansers, a partial list of which is, laundry soaps, hand soaps, naphtha soaps, borax soaps, soaps containing oils as solvents, soaps containing abrasives, liquid soaps,-

toilet soaps, floating soaps, salt water soaps, alkaline soaps, ammoniacal soaps, mechanics soaps, disinfecting soaps, industrial soaps, milled soaps,

V medicinal soaps, shampoo soaps, automobile l5 soaps, surgical'soaps, textile soaps, soap powders,

soap flakes, soap chips; soap mixtures with sodium carbonate with or without sodium sesquicarbonate, with or without caustic soda, with or without trisodium phosphate, with or without sodium silicates, with or without metaborates, and with or without borates; also soap pastes containing any of the usual ingredients such as abrasives, oils and water or any of the previously mentioned materials; also cleaning mixtures which may or may not contain-s0aps but may contain any of the above mentioned materials; also acid cleansers, as, for instance, oxalic acid, with or without acid sodium sulphate, which are often used as cleansers; also water solutionsof sodium or potassium bisulphite or hypochlorite o \0 Na for example, where R represents a carbon radical of from 10 to 18 carbon atoms, and for' Na other alkali metals maybe substituted; also all other detergents, cleaners and soap'substitutes or materials which are used in the place of soaps. v In the case of any of the above detergents, soaps .or admixtures therewith, and containing a water soluble thiotetraphosphoric acid compound, as, for instance, an alkali metal salt of a thiotetraphosphoric acid, it is to be understood that any proportions whatever of these various constituents maybe utilized in these admixtures, as desired.

While I have described my invention above in detail I wish it to be understood that many changes may be made thereinwithout departing ing a soap and an alkali metal salt of-a thiotetraphosphoric acid.

3. A washing liquid containing water and a water-soluble soap composition containing a soap and'an alkali metal salt of a thiotetraphosphoric acid.

4. A detergent composition containing a so-v atoms and a sodium salt of a thiotetraphosphoric acid.

5. A detergent composition containing a hypochlorite of an alkali metal and an alkali metal salt of a thiotetraphosphoric. acid.

AUGUSTUS H. FISKE. 

